Iran speeding up nuclear enrichment - US

IRAN could produce enough fissile material for a nuclear weapon within four months, experts have told US politicians.

The rate of Iran's uranium enrichment has accelerated despite cyber sabotage from the Stuxnet virus in 2009, the experts said today.

Based on the findings of the International Atomic Energy Agency (IAEA), "it's clear that Iran could produce a nuclear weapon very quickly should it wish to do so", said Stephen Rademaker of the Bipartisan Policy Center in Washington.

Iran has produced 3345 kilograms of uranium enriched to 3.5 per cent, according to the agency. It this were enriched further it would provide enough uranium for at least two atomic bombs, Rademaker told an armed services committee.

If the Iran leadership decided to go forward, "it would take them 35 to 106 days to actually have the fissile material for a weapon," he said.

David Albright, president of the Institute for Science and International Security (ISIS), told the committee "it would take Iran at least four months in order to have sufficient weapon grade uranium ... for a nuclear explosive device."

Uranium 235 must be enriched close to 90 per cent for use in an atomic bomb.

US Defense Secretary Leon Panetta has said Iran is about a year away from producing enough enriched uranium for a nuclear weapon, a threshold that Washington views as a "red line".

More than 9000 Iranian centrifuges are churning out 158 kilograms of 3.5 per cent enriched uranium a month, three times the production rate compared to mid-2009, when the Stuxnet virus struck the program, Mr Rademaker said.

The enrichment rate is "three times the rate of production prior to the Stuxnet virus, which many people have suggested somehow crippled their program".

"So Stuxnet may have set them back, but not by very much, at least not sufficiently."